M4.9 earthquake 220 km SSW of ‘Ohonua, Tonga
A magnitude 4.9 earthquake struck 220 km SSW of ‘Ohonua, Tonga on Thu, Mar 1, 1973, 4:20 PM GMT+13 (03:20 UTC), 33 km (21 mi) below the surface.
A larger quake followed: M5.6 198 km SSW of ‘Ohonua, Tonga. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 4.9 (mb), light
- Local time
- UTC
- 1973-03-01 03:20:19 UTC
- Depth
- 33.0 km (20.5 mi), shallow
- Epicenter
- 23.276° S, 175.419° W
- Region
- Tonga
- Tsunami flag
- No
- Status
- Reviewed by a seismologist
Did you feel it?
No one has reported feeling this quake to the USGS.
How well it is located
Reviewed by a seismologist.
- Depth from
- OPERATOR_ASSIGNED
- Stations used
- 14
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.9 and up: 2 in the 60 days after this one and 0 in the 30 days before it.
After
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp00000sk. Read Tue, Sep 22, 2026, 9:30 PM UTC.